[PATCH] mm: add populated_zone() helper

There are numerous places we check whether a zone is populated or not.

Provide a helper function to check for populated zones and convert all
checks for zone->present_pages.

Signed-off-by: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 8d6caa414c4c93754014a97b30f48f58b64d1ac2..c34f4a2c62f8e252bc9c260ebad20d419a180750 100644 (file)
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -388,6 +388,11 @@ static inline struct zone *next_zone(struct zone *zone)
 #define for_each_zone(zone) \
        for (zone = pgdat_list->node_zones; zone; zone = next_zone(zone))
 
+static inline int populated_zone(struct zone *zone)
+{
+       return (!!zone->present_pages);
+}
+
 static inline int is_highmem_idx(int idx)
 {
        return (idx == ZONE_HIGHMEM);

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b9fd2c238f137ba135234dc8f2b1a4dbb749a462..8f3de5af92ddbdd77b6b0d5282133888515e48be 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1358,7 +1358,7 @@ void show_free_areas(void)
                show_node(zone);
                printk("%s per-cpu:", zone->name);
 
-               if (!zone->present_pages) {
+               if (!populated_zone(zone)) {
                        printk(" empty\n");
                        continue;
                } else
@@ -1435,7 +1435,7 @@ void show_free_areas(void)
 
                show_node(zone);
                printk("%s: ", zone->name);
-               if (!zone->present_pages) {
+               if (!populated_zone(zone)) {
                        printk("empty\n");
                        continue;
                }
@@ -2134,7 +2134,7 @@ static int frag_show(struct seq_file *m, void *arg)
        int order;
 
        for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
-               if (!zone->present_pages)
+               if (!populated_zone(zone))
                        continue;
 
                spin_lock_irqsave(&zone->lock, flags);
@@ -2167,7 +2167,7 @@ static int zoneinfo_show(struct seq_file *m, void *arg)
        for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
                int i;
 
-               if (!zone->present_pages)
+               if (!populated_zone(zone))
                        continue;
 
                spin_lock_irqsave(&zone->lock, flags);

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5c8a412b43f4fe3564da89a3a5e3c99585df71fe..7681d8ee04fed8823cc412c35330cfd10f621a5f 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -897,7 +897,7 @@ shrink_caches(struct zone **zones, struct scan_control *sc)
        for (i = 0; zones[i] != NULL; i++) {
                struct zone *zone = zones[i];
 
-               if (zone->present_pages == 0)
+               if (!populated_zone(zone))
                        continue;
 
                if (!cpuset_zone_allowed(zone, __GFP_HARDWALL))
@@ -1069,7 +1069,7 @@ loop_again:
                        for (i = pgdat->nr_zones - 1; i >= 0; i--) {
                                struct zone *zone = pgdat->node_zones + i;
 
-                               if (zone->present_pages == 0)
+                               if (!populated_zone(zone))
                                        continue;
 
                                if (zone->all_unreclaimable &&
@@ -1106,7 +1106,7 @@ scan:
                        struct zone *zone = pgdat->node_zones + i;
                        int nr_slab;
 
-                       if (zone->present_pages == 0)
+                       if (!populated_zone(zone))
                                continue;
 
                        if (zone->all_unreclaimable && priority != DEF_PRIORITY)
@@ -1258,7 +1258,7 @@ void wakeup_kswapd(struct zone *zone, int order)
 {
        pg_data_t *pgdat;
 
-       if (zone->present_pages == 0)
+       if (!populated_zone(zone))
                return;
 
        pgdat = zone->zone_pgdat;